Development of liquid crystal display devices that use so-called plastic film substrates has been proceeding for many years in an effort to utilize a thin and lightweight construction. In recent years, other features, such as an unbreakable and bendable structure and great freedom in planar shape design, have also been attracting attention, and many applied products have been proposed.
In a liquid crystal display device constructed by sealing a liquid crystal between film substrates, it is known to provide a protective film of a transparent conductive material such as ITO in order to reduce the infiltration of air into the region where the liquid crystal is sealed (for example, patent document 1). In the liquid crystal display device described in patent document 1, protective layers formed from an inorganic transparent conductive material having extremely low permeability, such as ITO, are provided in a non-display area where the opposing electrodes on the top and bottom film substrates are not formed, thereby reducing the infiltration of air through the film substrates and thus attempting to suppress the occurrence of display defects due to air bubbles.
Patent document 1: Japanese Unexamined Patent Publication No. 2000-284310 (FIG. 2)